In both human AE and mouse models, MAPK pathway activation drives macrophage polarization toward an M2 phenotype [28], leading to the secretion of transforming growth factor-α (TGF-α) and TGF-β—key mediators that stimulate hepatic stellate cell (HSC) proliferation, transdifferentiation, and fibrogenesis [29]. Here, TGFA is linked to acrodermatitis enteropathica.